Electrical box for concrete walls

ABSTRACT

An electrical outlet box for accommodating an electrical fixture which includes a generally rectangular box having a back wall, a perimetrical side wall surrounding said back wall defining an open front face and a box interior, said side wall includes a first and second set of generally parallel spaced apart wall portions; and a slidable extension nested within said generally rectangular box, that can be moved from within the generally rectangular box to an extended position beyond the open front face.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/712,777 filed on Aug. 31, 2005, entitled “Electrical Box For ConcreteWalls”. Also, this application claims the benefit of and is aContinuation of U.S. patent application Ser. No. 11/512,473, filed onAug. 30, 2006, the contents of which are incorporated herein byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to an electrical outlet box forhousing electrical fixtures such as a switch or a receptacle. Moreparticularly, the present invention relates to an improved electricaloutlet box for use on concrete wall.

BACKGROUND OF THE INVENTION

It has long been known to house electrical fixtures such as switches andreceptacles in an electrical outlet box. The outlet box permits theinsertion of electrical wires into the box which are terminated toelectrical fixtures. The fixtures then may be mounted to the box whichprovides protection to the fixtures as well as the wires terminatedtherein. The outlet box is then mounted to a wall at a convenientlocation to provide access. Most outlet boxes accommodate one or moreelectrical fixtures, which terminate standard 110 volt electrical wires.

Outlet boxes are available in a variety of configurations and sizes. Theselection of which type of box to use is dependant upon the specifics ofthe application. The most commonly employed box is a single-gang outletbox, also referred to as a standard outlet box. The single-gang box isideal for applications in which only one receptacle is required for theapplication. Standard outlet boxes have opening dimensions ofapproximately 3″×2-¼″ and are available in a variety of depths.Double-gang and triple-gang boxes are also available, and they typicallyhave the capacity to hold two and three receptacles respectively. A fourinch (4″) square box is also commonly employed for multiple receptacleapplications.

Typically, outlet boxes are mounted by affixing mounting ears to a wallstud or other structural member. However, for some applications, such asexterior uses, there is a requirement to install electrical boxes onpoured concrete walls, wherein the outlet box, may be mounted within aconcrete structure. This is accomplished by attaching the box to a formin the desired location. The form is usually a wooden temporarystructure used to contain the poured concrete in the desired shape thatis removed after the concrete has hardened. The outlet box remains inthe concrete after removal of the form.

It is necessary when using an electrical box in such an application toinsure that it is securely affixed to the form to resist being displacedduring the concrete pour. Presently, electrical boxes used by manycontractors for installation in concrete walls are not well adapted foruse in concrete wall. Specifically, the prior art boxes lack featuresthereby making them difficult to use in concrete wall applications, orresult in additional work for the contractor. For example, many priorart boxes lack ears or other suitable attachment means for firmly andsecurely attaching the electrical box to the wooden form prior topouring the concrete. This can result in the contractor having to useless than suitable means to attach the box to the form which can resultin a misplaced box, or one that moved during the concrete pour andsubsequently became filled with concrete that the contractor must removein order to utilize the box.

Therefore, it would be desirable to have an electrical box for use inconcrete walls, incorporating features for securely mounting theelectrical box to a form, such that it remains stable and firmlyattached to the form during the concrete pouring process. Additionally,it is desirable that the electrical box used in a concrete wall preventinfiltration of concrete into the interior of the box during theconcrete pouring process, thereby preventing the box from becomingfilled with concrete and thus unusable. It is further desirable that theelectrical box can be easily modified to extend the open front perimeterof the box after the concrete is poured and hardened such that theperimeter will be flush with the finished wall surface to conform toelectrical code requirements.

SUMMARY OF THE INVENTION

Applicant has overcome the shortcomings of prior art outlet box with thepresent invention by incorporating features for securely attaching theelectrical box to a concrete form and further includes a built inextension device that can be pulled out from the front of the box toincrease the depth of the box, once it is set in place without the needfor attaching a separate extension.

The present invention therefore provides an electrical outlet box foraccommodating an electrical fixture comprising a generally rectangularbox having a back wall, a perimetrical side wall surrounding said backwall defining an open front face and a box interior, said side wallcomprised of a first and second set of generally parallel spaced apartwall portions; and a slidable extension nested within said generallyrectangular box, that can be moved from within the generally rectangularbox to an extended position beyond the open front face.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the electrical box according to thepresent invention, with the slide extension in a retracted position.

FIG. 2 is a perspective view of the electrical box according to thepresent invention, with the slide extension in an extended position.

FIG. 3 is a cross sectional view of a typical installation of theelectrical box of the current invention with the concrete forms in placealong section 3-3 of FIG. 1.

FIG. 4 is a cross sectional view of a typical installation of theelectrical box of the current invention with the concrete forms removedalong section 3-3 of FIG. 1.

FIG. 5 is a cross sectional view of a typical installation of theelectrical box of the current invention with a finish surface installedover the concrete along section 5-5 of FIG. 2.

FIG. 6 is a top cross sectional view of the electrical box according tothe present invention, with the slide extension in a retracted positionalong section 6-6 of FIG. 1.

FIG. 7 is a top cross sectional view of the electrical box according tothe present invention, with the slide extension in an extended positionalong section 7-7 of FIG. 2.

FIG. 8 is a perspective view of the interior of the electrical boxaccording to the present invention.

FIGS. 9A and 9B are close-up side and top views respectively of acomponent part of the electrical box according to the present invention.

FIG. 10 is a cross sectional perspective view of an alternate embodimentof the electrical box of the current invention, with the slide extensionin a retracted position along section 6-6 of FIG. 1.

FIG. 11 is a cross sectional perspective view of an alternate embodimentof the electrical box of the current invention, with the slide extensionin an extended position along section 7-7 of FIG. 2.

FIG. 12 is a perspective cross sectional view of the electrical boxaccording to the present invention, with the slide extension in aretracted position along section 6-6 of FIG. 1.

FIG. 13 is a perspective cross sectional view of the electrical boxaccording to the present invention, with the slide extension in anextended position along section 7-7 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

There will be detailed below the preferred embodiments of the presentinvention with reference to the accompanying drawings. Like members aredesignated by like reference characters in all figures;

Turning now to FIG. 1, there is shown an embodiment of the outlet box ofthe present invention. It should be noted that the present invention isshown and described with respect to a single gang outlet box, howeverthe invention can be adapted to multiple gang boxes such as for examplea double or triple gang box. The single gang embodiment shown anddescribed, is exemplary and not meant to be limiting to single gangversion.

There is shown an outlet box 100 which is generally a rectangular memberhaving a back wall 102, a pair of spaced apart side walls 104 extendingfrom back wall 102, and opposed top and bottom walls 106 and 108. Backwall 102, side walls 104 and top and bottom walls 106 and 108 form a boxinterior 110 having an open front face 112 which accommodates therein anelectrical fixture. Open front face 112 has a dimension substantiallyequivalent to the opening of a single-gang outlet box. The interiorlength and width of the opening will vary depending on if receptaclemounting flanges disposed on the box are interior or exterior to the boxopening. However, the outlet box depicted here is illustrative and notintended to be limiting. It will be appreciated that it would beapparent to have an outlet box according to the present invention havingalternate dimensions according to the application of such outlet box.Also visible in the interior of electrical box 100 is slideableextension 113. The extension 113 is shown in the retracted positionwithin the box. As will be further shown and described with respect toFIG. 6, in the retracted position, the extension is held in place byprotrusion 115 cooperatively engaging cavity 111. When the extension ispulled outside the box 100, the protrusion 115 snaps into a cavity 117in side wall 104 and cooperatively engages the cavity 117 to lock theextension in place. Box 100 is provided with at least two cavities 111for the retracted position and cavities 117 for the extended position onopposite side walls 104 which engage a similar number of protrusions 115on extension 113.

As is well known in the art, outlet box 100 may include one or moreaccess openings, typically known as knockouts 114 which permit entry ofelectrical wires and cables (not shown) into box interior 110. Inaddition, knockouts 114 include secondary smaller knockouts 115,centrally positioned on knockout 114. Knockout 127 is oval in shape andadapted to receive the blade of a straight blade screwdriver. Knockout127 seals electrical box 100 against the infiltration of concrete duringthe pour. In use the installer of electrical box 100 would first removeknockout 127 with a straight blade screw driver, then insert the bladeinto the opening resulting from the removal of knockout 127 and pry outknockout 114.

The exterior surfaces of side walls 104 include nails 116 and 118respectively which allow the box to be secured to a concrete form or thelike by driving the nails into the form prior to the concrete beingpoured. The nails 116 and 118 are attached to the box 100 by collars119, which permit the nails to slide with respect to the box 100.Therefore, the nails can be hammered forward into a form as the openfront face 112 is pressed against a form. In addition, each nail 116,118 is scored or notched 121 to create a stress raiser. The stressraiser is used to facilitate breaking the nail 116, 118 after the formhas been removed and the electrical box 100 set in concrete. The scoremark 121 is positioned along the nail's length such that it aligns withthe open front face 112 when the nail is fully extended into the form.In that way, when the form is removed, the score mark is even with thecured concrete and can be broken off flush with the concrete wall. Theinterior surfaces of extension 113 include component retaining flanges120 and 122 which include threaded apertures 124 for receivingfasteners, usually screws, to securely mount electrical componentswithin the outlet box. In addition, flange 125 is provided, extendingfrom back wall 102 beyond bottom wall 108 and top wall 106 (not visiblein this view). Flange 125 provides an additional anchor point for theelectrical box 100 to mechanically be affixed to the concrete.

Turning now to FIG. 2, there is shown the electrical box 100 accordingto the present invention wherein extension 113 is shown in the extendedposition. In the extended position, the extension 113, protrudes beyondopen front face 112. By extending the extension 113, the protrusion 115comes into cooperative alignment with cavity 117. The protrusion 115then snaps into cavity 117 in side wall 104 and locks the extension 113in place.

Turning now to FIG. 3, there is shown a cross sectional view of theelectrical box along section 3-3, according to the present inventionshowing a typical installation of an outlet box 100 in a concrete wallapplication. FIG. 3 shows a side view of the electrical box 100 encasedwithin forms 302 and 304. The front form 302 and rear form 304 are usedto retain poured concrete 306 to construct a vertical wall. As is wellknown, such forms may be constructed of wood stud, planks or sheets suchas plywood. Electrical box 100 is fastened to front form 302. The outletbox 100 must be securely fastened to the form when the concrete 306 ispoured. The electrical box 100 is nailed to the form by driving thenails 116, 118 through apertures provided on exterior collars 119 ofelectrical box into the form. Secure attachment of the box 100 to theform 302 maintains the box 100 in proper position during the concretepour.

Also shown in FIG. 3 is a ground screw 308, which is positioned at therear of the electrical box 100 along back wall 102 for attaching aground connection to an electrical device installed in electrical box100. Also visible in the side view are nails 116 which pass throughcollar 119. A wire is inserted into the electrical box 100 throughknockout holes 114, which would be fitted with a connector (not shown).The wire would typically be inserted through a conduit (not shown) whichwould be fastened to the connector. The wires can be installed before orafter the concrete is poured. It should be noted that the wire can berouted into the electrical box through knockout holes 114 positioned onany wall of the electrical box, such as for example side wall 104 orback wall 102. In another embodiment, wires could also be affixed withinelectrical box 100 by way of a locking clamp (not shown) for firmlyaffixing the wire such as, for example Romex cable. The locking clampwould typically include a screw which is tightened to clamp the wire inplace and prevent it from being pulled out during the constructionprocess. The side view of FIG. 3 further shows extension 113 in aretracted position. Furthermore, as can be seen the extension 113 has asemicircular cutout 314 which corresponds to the position of theknockout hole 114. In that way, when the extension is in the retractedposition as shown in FIG. 3, it does not interfere with the use of theknockout hole 114. Also seen in the side cross sectional view areprotrusion 115 snaps of extension 113 and cavity 117 in side wall 104.In this view can be seen that when extension 113 is in the retractedposition, protrusion 115 and cavity 117 are not cooperatively engaged,but are aligned such that the translational movement of extension 113will bring protrusion 115 into cooperative engagement with cavity 117 tolock the extension 113 in place. Nails 116 and 118 are shown in anextended position, protruding through form 302, and thereby holdingelectrical box 100 flush against the form 302, such that when the formin removed, the box interior is accessible to the contractor to accesswires and install electrical components.

Turning now to FIG. 4, there is shown the electrical box 100 accordingto the present invention in a typical installation wherein the concretehas hardened, and the forms are removed. In this view the concrete wallfront 402 and rear 404 surface are exposed. Removal of the forms alsoexposes the front of outlet box, as well as nails 116 and 118 used toaffix the electrical box to front form 302. The removal of the formsexposes the shank and point of the nails 116 and 118. In accordance withthe present invention, as will be explained further with reference tothe FIG. 9, the shank of fastener nails 116 and 118 which extends beyondconcrete front wall 402 can be removed by grasping the extended shankand forcibly bending the shank from side to side, thereby causing theshank to break at the stress raiser score mark or notch 121.

Turning now to FIG. 5, there is shown a cross sectional view alongsection 5-5 of the electrical box 100 according to the present inventionin a typical installation wherein the wall finishing material 502, suchas for example sheetrock has been installed on wall front 402. In thisview extension 113 is shown in the extended position, wherein protrusion115 of extension 113 and cavity 117 in sidewall 104 are in cooperativeengagement, thereby locking the extension 113 in place. To extend theelectrical box according to the current invention, the contractor needonly pull extension 113 out from the electrical box 100 and snap it inplace by aligning the protrusion 115 with cavity 117. This process iseasier and less time consuming than prior art methods, which require anextension piece to be affixed to the front of the electrical box usuallyby screwing the extension onto the electrical box. In the extendedposition, it can be seen that electrical box 100 flanges 120 and 122 arealigned with the outside plane 504 of wall finishing material 502.Furthermore, it can be seen that extension 113 extends electrical box100 to fully cover the gap from the front open front face 112 to theoutside plane 504 of finishing material 502 in conformance withelectrical code requirements.

Turning now to FIG. 6, there is shown top cross sectional view ofelectrical box 100 along section 6-6 of FIG. 1. In this view, extension113 is shown in the retracted position, wherein protrusion 115 isvisible extending from extension side wall 602, and into cavity 111 inelectrical box sidewall 104. Protrusion 115 is formed of a resilient tabthat angles slightly away from the plane of extension sidewall 602 andis biased to exert a force toward sidewall 104. In the retractedposition, the extension is held in place by protrusion 115 cooperativelyengaging cavity 111.

Cavity 117 is visible in sidewall 104, located toward open from face 112with respect to protrusion 115. The cavity 117 corresponds in size toprotrusion 115 such that when the translational movement of extension113 moves protrusion 115 into alignment with cavity 117, the resilienttab moves outward into cavity 117 thereby locking extension 113 in theextended position. In addition, the wall 606 of cavity 111 is angled toprovide a ramp for protrusion 115 to disengage from cavity 111 when theinstaller exerts a force on extension 113 to pull the extension out fromelectrical box 100. In this way the force required to pull out theextension is minimized, while still securely locking the extension inthe retracted position prior to use.

Turning now to FIG. 7, there is shown top cross sectional view ofelectrical box 100 along section 7-7 of FIG. 2. In this view, extension113 is shown in the extended position, wherein protrusion 1 5 is visibleextending from extension sidewall 602, into cavity 117 thereby lockingextension 113 in the extended position. As is depicted in FIGS. 6 and 7,the distance 702 that extension 113 extends from open front face 112corresponds to the positioning of protrusion 115 and cavity 117. Theplacement of protrusion 115 can thus be modified to provide for a longeror shorter extension distance 702. The closer to the inside edge 704 ofextension 113 that protrusion is placed, the longer the distance 702from open front face 112 of electrical box 100 to the extension frontedge 706. In this way, the electrical box 100 according to the presentinvention can be adapted to use for various thickness finishing material502. It is typical that sheetrock of ½″, ⅝″ or ¾″ is used in mostapplications, however other variations are possible. For example, theelectrical box 100 according to the current invention can be adapted foruse where sheetrock is overlaid with another material such as ceramic orstone tile. In this type of application, protrusions 115 will be locatedon extension sidewall 602 at a distance from inside edge 704 such thatextension 113 extends to a distance corresponding to the depth of thefinish material layers 502.

Turning now to FIG. 8, there is shown a front perspective view of theelectrical box 100 according to the current invention. Shown in thisview is the electrical box interior 110. In this view, knockouts 114 arevisible on the top 106 and bottom 108 of electrical box 100. Allknockouts on the box according to the present invention are design towithstand the conditions specific to the use of electrical boxes in aconcrete wall. All knockouts 114 are punched to the outside ofelectrical box 100, to prevent the knockout opening from the force ofthe poured concrete pressing against the outside of the electrical boxduring construction. Furthermore, as previously mentioned, knockouts 114incorporate a smaller oval or oblong shaped knockout 127 locatedcentrally within knockouts 114. Knockouts 127 are punched to the insideof the box to facilitate its opening by the contractor, and are adaptedto receive a flat head screw driver blade. The contractor installing anelectrical box according to the current invention can therefore have asealed electrical box that will prevent concrete from infiltrating intothe box interior 110. Once the contractor has removed knockout 127 thecontractor can use the oblong hole obtained to pry open knockout 114with a screw driver.

Also shown in FIG. 8 is a moveable ground screw mounting tab 804 formounting grounding screws 806, located on back wall 102. Tab 804 iscomprised of a frangible slit 808 on back wall 102. The tab 804 providesthe contractor with additional room to secure the ground wire to theelectrical box, once the concrete has been poured and hardened. Intypical conditions it is difficult to screw the grounding screws infully to where the head touches the bottom of the box because the screwcannot penetrate the hardened concrete outside the box. To eliminatethat difficulty, the moveable ground screw mounting tab 804 in theelectrical box 100 according to the present invention can be bentforward by the user after the box is installed and the concretehardened. In that way, there will be enough room behind the screws tofully screw in the grounding screws and affix the ground wires.

Turning to FIG. 9 there is a shown a close-up view of side view 9A andtop view 9B of nails 116 and 118 used to secure electrical box 100 to aconcrete form by driving the nails into the form prior to the concretebeing poured. Each nail 116, 118 is scored 121 to create stress raiser.In side view 9A, the score 121 is shown as a “v” shaped cut extendingpartially through the shank of nails 116 and 118 and creates a stressraiser, which can be seen in FIG. 9B as a slit in the side of nails 116and 118. The stress raiser is used to facilitate breaking the nail afterthe form has been removed and the electrical box 100 set in concrete. Tothat end, the score mark 121 is positioned along the nails' length suchthat it corresponds to the open front face 112 when the nail is fullyextended into the form. In that way, when the form is removed, the scoremark is even with the cured concrete and can be broken off flush withthe concrete wall.

Turning now to FIG. 10, there is shown top cross sectional view of analternate embodiment of electrical box 100 along section 6-6 of FIG. I.In this view, extension 113 is shown in the retracted position, whereinprotrusion 115 is visible extending from extension side wall 602, andbearing against electrical box sidewall 104. Protrusion 115 is formed ofa resilient tab that angles slightly away from the plane of extensionsidewall 602 and is biased to exert a force against sidewall 104. In theretracted position, the extension is held in place by the frictionbetween protrusion 115 and sidewall 104.

Cavity 117 is visible in sidewall 104, located toward open from face 112with respect to protrusion 115. The cavity 117 corresponds in size toprotrusion 115 such that when the translational movement of extension113 moves protrusion 115 into alignment with cavity 117, the resilienttab moves outward into cavity 117 thereby locking extension 113 in theextended position.

Turning now to FIG. 11, there is shown top cross sectional view ofelectrical box 100 along section 7-7 of FIG. 2. In this view, extension113 is shown in the extended position, wherein protrusion 115 is visibleextending from extension sidewall 602, into cavity 117 thereby lockingextension 113 in the extended position. As is depicted in FIGS. 6 and 7,the distance 702 that extension 113 extends from open front face 112corresponds to the positioning of protrusion 115 and cavity 117. Theplacement of protrusion 115 can thus be modified to provide for a longeror shorter extension distance 702. The closer to the inside edge 704 ofextension 113 that protrusion is placed, the longer the distance 702from open front face 112 of electrical box 100 to the extension frontedge 706. In this way, the electrical box 100 according to the presentinvention can be adapted to use for various thickness finishing material502. It is typical that sheetrock of ½″, ⅝″ or ¾″ is used in mostapplications, however other variations are possible. For example, theelectrical box 100 according to the current invention can be adapted foruse where sheetrock is overlaid with another material such as ceramic orstone tile. In this type of application, protrusions 115 will be locatedon extension sidewall 602 at a distance from inside edge 704 such thatextension 113 extends to a distance corresponding to the depth of thefinish material layers 502.

Turning now to FIG. 12, there is shown a perspective view of theelectrical box 100 along section 6-6 of FIG. 1. In this view, extension113 is shown in the retracted position, wherein protrusion 115 isvisible extending from extension side wall 602, and into cavity 111 inelectrical box sidewall 104. Protrusion 115 is formed of a resilient tabthat angles slightly away from the plane of extension sidewall 602 andis biased to exert a force toward sidewall 104. In the retractedposition, the extension is held in place by protrusion 115 cooperativelyengaging cavity 111.

Cavity 117 is visible in sidewall 104, located toward open from face 112with respect to protrusion 115. The cavity 117 corresponds in size toprotrusion 115 such that when the translational movement of extension113 moves protrusion 115 into alignment with cavity 117, the resilienttab moves outward into cavity 117 thereby locking extension 113 in theextended position. In addition, the wall 606 of cavity 111 is angled toprovide a ramp for protrusion 115 to disengage from cavity 111 when theinstaller exerts a force on extension 113 to pull the extension out fromelectrical box 100. In this way the force required to pull out theextension is minimized, while still securely locking the extension inthe retracted position prior to use.

Turning now to FIG. 13, there is shown a perspective cross sectionalview of electrical box 100 along section 7-7 of FIG. 2. In this view,extension 113 is shown in the extended position, wherein protrusion 115is visible extending from extension sidewall 602, into cavity 117thereby locking extension 113 in the extended position. As is depictedin FIGS. 6 and 7, the distance 702 that extension 113 extends from openfront face 112 corresponds to the positioning of protrusion 115 andcavity 117. The placement of protrusion 115 can thus be modified toprovide for a longer or shorter extension distance 702. The closer tothe inside edge 704 of extension 113 that protrusion is placed, thelonger the distance 702 from open front face 112 of electrical box 100to the extension front edge 706. In this way, the electrical box 100according to the present invention can be adapted to use for variousthickness finishing material 502. It is typical that sheetrock of ½″, ⅝″or ¾″ is used in most applications, however other variations arepossible. For example, the electrical box 100 according to the currentinvention can be adapted for use where sheetrock is overlaid withanother material such as ceramic or stone tile. In this type ofapplication, protrusions 115 will be located on extension sidewall 602at a distance from inside edge 704 such that extension 113 extends to adistance corresponding to the depth of the finish material layers 502.

It will be appreciated that the present invention has been describedherein with reference to certain preferred or exemplary embodiments. Thepreferred or exemplary embodiments described herein may be modified,changed, added to or deviated from without departing from the intent,spirit and scope of the present invention. It is intended that all suchadditions, modifications, amendments, and/or deviations be includedwithin the scope of the claims appended hereto.

1. An electrical outlet box for accommodating an electrical fixturecomprising: a generally rectangular box having a back wall, aperimetrical side wall surrounding said back wall defining an open frontface and a box interior; a slidable extension nested within saidgenerally rectangular box, that can be moved from within said generallyrectangular box to an extended position beyond said open front face,wherein said slideable extension can be secured in said extendedposition beyond said open front face; and a movable ground screwmounting tab.
 2. An electrical outlet box of claim 1, having outwardlydirected collars extending from one pair of parallel wall portionsadjacent said open front face; and movable fastening structures slidablyheld within said collars for rigidly mounting said electrical outlet boxto a structural member.
 3. An electrical outlet box of claim 2, whereinsaid movable fastening structures have a notch for facilitating removalof a portion of said movable fastening structures.
 4. An electricaloutlet box of claim 1, further including frangible elements on said sidewall and said back wall for creating an opening into said box interior.5. An electrical outlet box of claim 4, wherein said frangible elementsare generally circular.
 6. An electrical outlet box of claim 5, whereinsaid frangible elements include an oval shaped frangible port locatedapproximately at the center of said frangible element.
 7. An electricaloutlet box of claim 1, wherein said extended position beyond said openfront face is a predetermined distance that corresponds to the depth ofa wall finish material.
 8. An electrical outlet box of claim 3, whereinsaid notch is located at a predetermined point along said movablefastening structures that corresponds to the distance said fasteningstructures protrude from a finished wall.